The present invention relates to a seat slide device for vehicles and more specifically to a lock mechanism of the seat slide device.
In these days, a vehicle seat is increasingly required to be capable of changing its layout variously, so that not only a front seat but a second seat, third seat and the like are provided with seat slide devices. Thus, the seat slide device is required to be disposed under various restrictions, for example, to be embedded in a floor surface of a vehicle or to be disposed within a restricted space.
For this reason, in order to attain disposition of the seat slide device under such a severe condition, it has heretofore been proposed a seat slide device wherein a lock mechanism is disposed in a space between a lower rail on a vehicle floor side and an upper rail on a seat side, so that the lock mechanism does not have any portion protruding outward from the upper rail.
A brief description being made to the seat slide device, the lock mechanism includes a locking finger swingably installed on a lower end of one upper rail side wall. The locking finger is bent so as to have an end portion extending from the inside of the upper rail toward the above-described one upper rail side wall. The end portion of the locking finger further extends through an engagement hole formed in the above-described one upper rail side wall and engaged in an engagement hole (engaged portion) formed in a lower rail side wall at any arbitrary position thereof. The locking finger is urged by a spring disposed inside the upper rail in the direction to engage the engagement holes. In case of unlocking of the lock mechanism, the locking finger is adapted to swing against the bias of the spring. Namely, during the time an unlocking operation of the locking fingers is not performed, the locking finger extends from the inside of the upper rail to the outside thereof and is thereby engaged in the engagement holes provided to the upper rail side wall and the lower rail side wall. By an unlocking operation carried out by means of a release lever, the locking finger is released from engagement with the lower rail. In the meantime, the lower rail is provided with a plurality of engagement holes that are arranged in a range within which the slide position of the upper rail can be changed relative to the lower rail.
Accordingly, in the seat slide device, the locking mechanism is almost disposed inside the upper rail and the lower rail and is therefore not protruded outside therefrom. As a result, an effective space can be retained at a location outside the upper rail, thus enabling the seat slide device to be disposed in a restrictive vehicle space with ease.